POS0248 SUBCLINICAL GIANT CELL ARTERITIS IN PATIENTS WITH POLYMYALGIA RHEUMATICA SHOWS A DIFFERENT ULTRASONOGRAPHIC PATTERN THAN PATIENTS WITH CLASSICAL GIANT CELL ARTERITIS
Authors: E. De Miguel, P. Macchioni, E. Conticini, C. Campochiaro, R. Karalilova, S. Monti, C. Ponte, G. Klinowski, I. Monjo, P. Falsetti, A. Tomelleri, Z. Batalov, A. Hocevar
Journal: Annals of the Rheumatic Diseases (2022)

Background Polymyalgia rheumatica (PMR) can be associated with giant cell arteritis (GCA), even in the absence of clinical suspicions of vasculitis. In addition, some studies have shown an association of PMR with the predominantly large vessel involvement. Objectives The objective of our study was to assess the presence of subclinical GCA in patients with PMR and to compare its pattern of vascular involvement to patients with classical GCA. Methods Eight rheumatology European centers participated in the study. Cohort A represented consecutive newly diagnosed patients with PMR who fulfilled the 2012 EULAR/ACR Provisional Classification Criteria for Polymyalgia Rheumatica 2 and had no symptoms or signs suggestive of GCA. Ultrasound (US) examination of four vessel territories (i.e. temporal, carotid, subclavian and axillary arteries) was performed bilaterally. Cohort B included all consecutive patients with the diagnosis of GCA evaluated on the fast-track clinic of one of the hospitals (HULP). The halo sign was considered as positive US finding for GCA 3 . In addition, intima-media thickness of arteries was measured, with a cut-off ≥0.34 mm for temporal arteries (TA) frontal and parietal, 0.42mm for common TA, and ≥1 mm for common carotid, axillary and subclavian arteries for positive result. The clinical characteristics of PMR patients were recorded and the frequency of subclinical GCA determined. Results Cohort A included 41 PMR patients with subclinical GCA. Cohort B was formed by 97 GCA. The characteristics of the patients are shown in the Table 1. Figure 1 shows the different subtypes of vessel involvement in patients with PMR and subclinical GCA and in patients of the fast-track clinic with the diagnosis of GCA in a single hospital. Figure 1. Subtypes of vessel affectation in Subclinical GCA in PMR and in classical GCA Table 1. Clinical characteristics of patients of Cohort A (Subclinical GCA in PMR n = 41/216) and B (GCA in the fast-track clinic n = 97) Cohort A (n = 41) Cohort B (n = 97) Sex female (%) 17 (41.5%) 53 (54.6%) Age (years) mean ± SD 74±6.7 79 ± 12 CRP mg/L 49.6±49.1 46 ± 81.6 Polymyalgia rheumatica 41 (100%) 47 (48.5%) Constitutional symptoms 19 (35.18%) 35 (36.1%) Subclinical PMR has a predilection for affectation of large vessels, followed by isolated cranial pattern (ie. Isolated temporal artery involvement) and by the mixed (cranial and extra-cranial) form. On the contrary, in classical GCA an isolated cranial involvement represents the more common pattern, followed by the mixed and finally isolated large vessel involvement. Conclusion Subclinical GCA in PMR shows a principal isolated extra-cranial involvement and with clearly different pattern than classical GCA. Acknowledgements To the GCA/PMR study group Disclosure of Interests None declared